The subject matter disclosed herein relates to elevator systems. More particularly, the present disclosure relates to sheave configurations for elevator systems.
A typical elevator system includes an elevator car that moves along a hoistway. The elevator car is suspended in the hoistway and driven along the hoistway by one or more tension members, such as a coated steel belt. The coated steel belt is operably connected to the elevator car, and driven by a motor to propel the elevator car along the hoistway. Coated steel belts in particular include a plurality of wires located at least partially within a jacket material. The plurality of wires is often arranged into one or more strands and the strands are then arranged into one or more cords. In an exemplary belt construction, a plurality of cords is typically arranged equally spaced within a jacket in a longitudinal direction.
The motor drives a sheave, in this case a traction sheave, over which the coated steel belt is routed. The belt gains traction at the traction sheave, such that rotation of the traction sheave consequently drives movement of the elevator car. The coated steel belt is then routed over one or more idler or deflector sheaves to guide the belt between the traction sheave and the elevator car. The idler or deflector sheaves are utilized to route the tension member and to maintain a desired tension thereat. Such sheaves are typically formed from steel, with a coating, such as a nickel plating, applied to the outer sheave surface that is interactive with the tension member. Due to the high surface energy of the metal surface, the tension member to sheave interface can generate noise as a result of strain energy buildup and release in the jacket.